from nelson mandela's extraordinary example of moral courage, kindness and humility. bill clinton tweeted a picture and wrote, "i will never forget my friend madibaa," use the affectionate name by which mandela was known to his followers. mandela wasn't always on the u.s. side. in the 1980s president reagan supported apartheid regime, and eastern as protests broke out an college campuses across america demanding the u.s. punish the regime. ♪ ♪ free mandela >> reporter: "free nelson mandela" became a popular anthem for black and white americans. finally, congress, including key republicans, overrode reagan's veto imposing the economic sanctions that helped break the apartheid regime. that set the stage for mandela's triumphant visit to washington as his country's president. >> we are to one another brother and sister, a united rainbow nation that rises from the bond a age. >> bono, mandela's great friend wrote in the end nelson mandela showed us how to love, not to hate, not because he surrendered to rage or violence, but because he learned love would do a better job. savannah?